Urinalysis
Introduction to Urinalysis & Other Bodily fluids
Physical analysis/Macroscopic analysis- Analysis of being visible to the eye
Chemical analysis of urine- Thepresence of substances in the urine
Urine- Fluid that comprises the waste materials in the blood.- Ultrafiltrate of blood/plasma.
Brightfield Microscope- Isused in examining urine.
Functions of Kidneys
1. Homeostasis
2. Maintains blood pressure
3. Eliminates metabolic waste
4. Regulates Hormones- EPOErythropoietin (from RBC cells)- Aldosterone- ADH
The Urinary System
1. Kidney
➢ Nephrons- Thebasic functional unit of the kidney- Hasthecapacity to filter blood
1. Glomerulus- Atuftof anastomosing capillaries- Capillary taft- Located inside the bowman’s capsule
2. Bowman's capsule- Semipermeable membrane that allows passage of substances with MW of less than 70,000
Daltons.- Hasanature of a Non selective filter
➢ Glomerular filtrate- Fluid that exits the bowman’s capsule- Leads to the Proximal convoluted tubule
3. Proximal Convoluted Tubule- Site that reabsorbs the majority of the essential substances from the glomerular filtrate.
4. Loop of Henle- Site of major exchange of water and salt occurs.
1. Descending Loop of Henle- Freely permeable to water.
2. Ascending Loop of Henle- Salt reabsorption.
5. Distal Convoluted Tubule- 2Hormones are secreted
1. Aldosterone- Reabsorption of Na
2. ADH- Reabsorption of H2O
6. Collecting Tubules- Final concentration of urine occurs- Neurons meet here
2. Ureters- Narrow tubules that carry the urine from the kidneys to the bladder
3. Bladder- Triangle shaped, hollow organ located in the lower abdomen that stores urine.- Sphincter muscle is responsible for contracting in the bladder
4. Urethra- Hollow tube that allows urine to pass out of the body.
Urine composition- 96%water and 4% dissolved substances
Organic components
1. Urea- Primary organic component- 25-35gmper day
2. Creatinine- 1.5gm per day
3. Uric acid
4. Ammonia
5. Undetermined nitrogen
Inorganic components
1. Principle salt
2. Sodium chloride 15g
3. Potassium Calcium Magnesium
Factorsthataffecturinaryfunction
1. DietaryIntake
2. Physicalactivity
3. Bodymetabolism
4. Endocrinefunctions
TypesofUrineSpecimenCollectedtheinLaboratory
1. Random/SingleSpecimen-Collectedatanytimeoftheday-TheMostCommonlyreceivedspecimen
2. FirstMorningUrineSpecimen-IdealScreeningofSpecimen-MostConcentrated
3. FastingSpecimen/2ndMorning-Forglucosemonitoring-Youhavetofastfor8hrs
4. TimedSpecimen
1. 24-hrurinecollection-Collectsthefullvolumeofurine-Everythingthathasbeenvoidedwillbecollected-Quantifiesthetotalamountofsolutespresentinurine-Donetopeoplewithrenaldiseases
2. 12hour-Canbedayornightspecimen-UsedforAddiscountorquantitativecount-Chemicalpreservativesisused(40%formulae)
3. 4-hoururinecollection-Correlationofothertimedspecimenssuchasprotein
4. 2-hoururinecollection-Usedformonitoringinsulintherapyandglucosetesting
5. Afternoon(2-4pm)-Forurobilinogendetermination-Increasedamountofurobilinogenisseenbetween2-4pm
5. GlucoseTolerance-UsedinconjunctionwithOralglucosetolerancetest
6. Midstream Clean catch- Middle portion of urine- Forroutine urinalysis- MostCommon Specimen
7. 3-glass collection- Usedtodetermine prostatic infection
1. First voided urine
2. Middle Portion- ForUTI
3. Prostate Secretion- Forculture
8. Catheterized- Anelongated rubber tube is inserted into the urethra and into the bladder.- There is a collection bag from the catheter which is subjected for bacterial culture
9. Suprapubic- Directly collected from the bladder- Usedfor Bacterial culture and cytological studies
10. Pediatric- Routine analysis or culture
11. Drug Testing Specimen- 30to45mLor60mL- Fresh urine is supposed to be 32.5- 37 °C
Change in urinary composition will occur after 2 hrs without refrigeration
2-8 °C refrigeration (For no increase in bacterial growth)
Urine Analysis
3 Phases
I.
Physical Characteristics
1. Volume- Range for secretion of urine output 600-2000 mL- Normal daily output 1200-1500 mL
2. Color
1. Light yellow- Dilute random specimen
2. Dark yellow- Concentrated
3. Transparency- Normal transparency (Clarity)
Clear- Hazy- Cloudy- Turbid- Milky
4. Odor
➢ Faintly aromatic- Indication of faint urine
➢ Fruity sweet odor- Showspresence of ketone bodies
➢ Sweaty feet odor
➢ Oldbook odor
II.
1.035
(Concentrated)
5. Specific gravity- Measures the total amount of solute present in urine- 1.005
(Dilute)
Chemical
1. pH- Ismeasured to determine whether the urine is acidic, basic or alkaline- Random is 4.5- 8- Average is 6
2. Blood
Hematuria- Presence of intact RBC in urine (speckled pattern)
Hemoglobinuria- Presence of free hemoglobin (diffusing color)- Hemoglobin is the protein portion of the blood
3. Protein- Itshould be negative
1. Pre renal in origin- Presence of blood
2. Renal origin- Affects the kidneys
3. Post renal in origin- Affects the ureters and bladder
4. Nitrite- Presence of bacteria
5. Leukocytes esterase- Presence of bacteria
6. Glucose- Diabetes mellitus
7. Ketone- Diabetes mellitus
8. Bilirubin- Toscreen for Liver disease
9. Urobilirubin- Toscreen for liver disease Liver disease
III.
Microscopic
1. RBC- Viewed under HPO- Should be negative in a normal urine sample, positive results indicate bleeding.
2. WBC- Viewed under HPO- Should be negative, when bacteria is present WBC can be seen, the kind of WBC
present are neutrophils.
3. Casts- Viewed under LPO- There shouldn’t be any casts present- Ifpositive, it is an indication of Urinary retention.- Areformed in the Distal convoluted tubule and the collecting tubule- Protein matrix that surrounds the cast is the Tamm-Horsfall protein
4. Squamous epithelial cells- Viewed under LPO- Largest epithelial cell- Found in the urethra
5. Transitional epithelial cells- Viewed on LPO- Second largest- Found in the ureters or bladder
6. Renal tubular cells- Viewed under LPO- Smallest epithelial cell- Pathologic because its origin is in the kidneys, formed either in the proximal or
distal convoluted tubule.
7. Bacteria- Viewed under HPO- Seenin cases of bacterial infection
8. Yeast- Viewed under HPO- People who have fungal or yeast infections- Itis often confused with RBC, and budding is used to differentiate the two.- Yeast cells have branching Filamentous rods/mycelial form- Commonamong old people
9. Crystals- Viewed under LPO- There are cases where crystals are found in acidic urine or alkaline.- Calcium oxalate crystals are normally present in urine.- Trace amounts are fine but if high amounts are seen there should be a change in
diet.- Ammonium Biurate crystals resemble thorny apples .
10. Mucus threads- Viewed under LPO- Commonly present in women- Itis not a contamination, vaginal fluid- Canbeseen in men, in cases when there is excessive shedding of the epithelium.
Other Body Fluids
1. CSF- Itis collected by a physician- Collected in the lumbar area between the 3rd and 4th vertebrae.- Usedtodiagnose certain types of infection or inflammation in the central nervous system.
2. Semen- Istheliquid portion
1. Motility- Double head- Tapered head- Coiled tail- Double tail- Blunt head
2. Count
3. Morphology
3. Amniotic fluid- Fluid that surrounds the fetus- Actsas a cushion or support
4. Synovial- Fluid that surrounds the joints- Itested in the laboratory for hemorrhage inflammation or infection.
5. Serous
1. Pleural- Located in the lungs
2. Pericardial- Fluid that surrounds the heart
3. Peritoneal- Fluid that surrounds the abdomen- Othername is acidic fluid
6. Sputum & Bronchoalveolar lavage (washings of the lungs)
7. Gastric fluid analysis- Fluid within the stomach
8. Fecalysis/stool analysis
9. HCG pregnancy testing (Human Chorionic Gonadotropin)
10. ETA (Endotracheal Aspirate)- Whenapatient has a tube going down up into the brachial area
11. Wound discharge or pus
12. Sweat
13. Saliva
14. Vaginal discharge or vaginal secretions- To detect certain disorders such as bacterial vaginosis, pelvic inflammatory disease and
candidiasis